Muffler



Oct. 9, 1934. v. OLDBERG MUFFLER Fild July 2, 1931 2 Sheets-Sheet 1 I) 0 D o O a o o INVENTOR ATTORNEY OR [dlqzy MM 2 Sheets-Sheet Get 9, 1934. v. OLDBERG MUFFLER Filed July 2, 1931 INVENT ATTOIRNEY 000000 0 o ooooooo 0 000 1 0000000 oooooo W o 0 M 0000 c a o O u VI 0 0 o 0 Z 000 o o o a B 000 O o o u c o o o R 0 0o o e I/ g o a 0 O o o o a no 0 o o 0 ;e o o 7 v a a o o o y I O O o o K i0 0 o u o o 9 o I o 0 4 0 0 Z0 0 o 70 o o i o o o a o o o c o o i; v a a o w ,m v o O o a 0 o o a o D o o o a o o O O D O r R a o o o i... 0 0 c n 0 00000 0 a 0 o a 0 Q0 0 C o 0 O O O o o 0 o a 0 O o o o g Patented Got. 9, i934 i STAT @FFICE 1 Claim. (CL 137--160) This invention relates to mufiers and more particularly to automobile engine muiilers of the thru type.

Mufflers of the thru type, as generally constructed, include an outer shell having headers which are connected by and thru which passes an inner shen, the latter being entirely free of baffles etc. and being provided with perforations, between the headers, leading into the annular space between the shells. Mufiiers of this type are advantageous in that they are free from back pres- .sure, and it suitable means between the shells be provided to absorb or neutral se sounds arising the murders, the mufiler is found to be highly efficient as means for eliminating noises which. occur in er e operation.

an object of. .ie invention, therefore, is a muirler of the thru type provided with means in the aanuiar space between the shells, to neutraiize sounds. M re particularly, the invention aims provide rescnance chambers in the space between the shells, as contrasted with mufiiers, such have previo been provided, and which e sound absc g media disposed between still further object is a muffler of the character above described. which is provided with a basis at its end to prevent flames from passing out of the rnufi r.

A still further is a niulder having transverse diaphragms between the shells, the dia phragms being formed of ribs rolled inwardly or outwardly from one or more of the shells, as desired.

Stiil further objects will readily occur to those skilled in the art upon reference to the following description and the accompanying drawings in Y which Figs. 14 are longitudinal section views of "s forms of mufiiers.

Fig. 5 is a section on the line 5P5 of Fig. 3. Fig. 6 is a partial section view of another form of mufiier.

Figs. 7 to 9 show still other forms of mufliers, in section.

Referring to the drawings and more particularly to Fig. 1 it will be seen that the mufiier of this form includes an outer imperforate shell 10 provided with end headers 12 and 13 which are connected by an inner shell 14 passing thru both of the headers. In the annular space between the shells are diaphragms 16 and 18 which reinforce the mufiler and also form resonating chambers, indicated at R. A plurality of small, closely spaced perforations 19 in the shell leafiord communication between the interior of the shell 14 and the resonating chambers.

It will be seen that the gases from the engine pass thru the inner shell 14 without obstruction and that sounds within the muffier are attenu- 6G ated by resonance within the accurately and suitably located resonating chambers R, the fluid within such chambers acting upon the diaphragms 16 and 18.

In Fig. 2 there is disclosed a muffler including 66 an outer shell 20 having headers 21 thru which pass and connecting which is an inner shell 22. An intermediate shell 23 also connects the headers and in the two annular spaces between the shells are diaphragms 24 and 25. The inner shell 70 22 is provided with closely spaced minute perforations 26 which open into the resonating chambers between the diaphragms substantially as disclosed.

It will be observed that the diaphragms 24 have ,78 very little value as resonating diaphragms but are provided to reinforce the mufiier, whereas diaphragms 25, besides reinforcing the mufller, serve as true resonating diaphragms.

In Figs. 3 and 5, there is disclosed a mufllerfifl which has proven to be very efiicient. The muifler of this form includes an outer shell 30 provided with end headers 31, each of which is provided with a nipple 32. Within the shell 30 and spaced from the end headers, are auxiliary headers 33, these being connected by the inner shell 34 and the intermediate shell 35. The inner shell 34 is provided with minute perforations 36, opening into the space between the inner shells 34 and 35 which is filled with a sound absorbing media 37, '90 such as steel wool, mineral wool, or loosely packed fiber or the like. The space between the shells 30 and 35 contains two accurately located resonating diaphragms 38 which form resonating chambers R, communicating with the spaces between the headers 31 and 33 thru slots 39 in the outermost portions of the headers 33.

It will be seen that in this form the gases pass from one nipple 32 to the other without interference, there being no baflles in the path of flow of the gases. Certain of the gases, however, pass from the spaces between the headers 31 and 33, thru the slots 39 and into the resonating chambers R, to provide a medium for resonating vibrations in these chambers.

The form of Fig. 4, is very much like the form of Fig. 3, except that the sound absorbing media 37 is replaced by a plurality of resonating dia phragms 37a which form supplemental resonating chambers R1 communicating with the inner shell 34 thru the perforations 36.

In Fig. 6 there is shown a mufller which is very much like those disclosed in Figs. 3 and 4 except that in .the space between the slotted header 41 and the end header 42 a. conical perforated baflle 43 is disposed, the bafile opening towards the exit nipple 44. A baflle of this character serves the useful purpose of preventing flames which might be present in the mufller from passing out thru the nipple 44.

In Fig. 7 there is disclosed a mufiler which is very much like the mufiler of Fig. 2, except that the diaphragms in the space between the inner shell 50 and the intermediateshell '51 are formed by roller annular ribs 52 integral with the inner .shell and projecting outwardly therefrom and into engagement with the intermediate shell 51 forming resonating chambers R similar to those disclosed in Fig. 1. Resonating chambers of a trapezoidal cross section have proven to be very efliclent, much more so than resonating chambers of the rectangular cross section of Fig. 2.

In Fig. 8 there is disclosed a muffler which is more or less like the mufller of Fig. '7 except that the partitions between the inner shell 60 and the intermediate shell 61 are formed by rolled annular ribs 62 projecting inwardly from the intermediate shell and engaging the wall of the inner shell to form resonating chambers R of trapezoidal cross section.

Fig. 9 discloses a muiiler which is also very much like the form of Fig. 7 except that the diaphragms between the inner shell '70 and the intermediate shell 71 comprise annularribs 72 rolled outwardly from the inner shell and annular ribs 73 rolled inwardly from the intermediate shell. ribs engage one another and are secured to one another to form transverse partitions to form resonating chambers R which,

as disclosed, have a lozenge shaped cross section having all of the advantages of the trapezoidal cross section resonating chambers disclosed in Figs. '7 and 8.

Now having described the invention and the preferred embodiment thereof, it is to be understood that the said invention is to be limited, not,

to the specific details herein set forth, but only by the scope of the-claim which follows:

What I claim is: I

A through type silencer comprising an outer shell, and headers therefor, inlet and outlet pipes connected to the end headers, intermediate headers spaced from and between the end headers to provide end chambers outside of the intermediate headers, two relatively nested shells within the headers being apertured to provide communication between these chambers and the end chambers, the remainder of the attenuating chambers being substantially completely closed,

VIRGIL OLDBERG. 

